title: Quantitative Structure-Activity Relationship Studies of 4-Imidazolyl- 1,4-dihydropyridines as Calcium Channel Blockers.
abstract: OBJECTIVE
  The structure- activity relationship of a series of 36 molecules, showing L-type calcium channel blocking was studied using a QSAR (quantitative structure-activity relationship) method.
  
  
  METHODS
  Structures were optimized by the semi-empirical AM1 quantum-chemical method which was also used to find structure-calcium channel blocking activity trends. Several types of descriptors, including electrotopological, structural and thermodynamics were used to derive a quantitative relationship between L-type calcium channel blocking activity and structural properties. The developed QSAR model contributed to a mechanistic understanding of the investigated biological effects.
  
  
  RESULTS
  Multiple linear regressions (MLR) was employed to model the relationships between molecular descriptors and biological activities of molecules using stepwise method and genetic algorithm as variable selection tools. The accuracy of the proposed MLR model was illustrated using cross-validation, and Y-randomisation -as the evaluation techniques.
  
  
  CONCLUSIONS
  The predictive ability of the model was found to be satisfactory and could be used for designing a similar group of 1,4- dihydropyridines , based on a pyridine structure core which can block calcium channels.
authors.affiliation: Biotechnology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Farzin
authors.initials: F
authors.lastname: Hadizadeh
authors.forename: Saadat
authors.initials: S
authors.lastname: Vahdani
authors.forename: Mehrnaz
authors.initials: M
authors.lastname: Jafarpour
keywords: Dihydropyridines; Genetic algorithm; MLR; QSAR; pIC50